This invention relates generally to techniques for controlling the flow of vehicular traffic.
Traffic engineers use a variety of techniques to attempt to alleviate traffic congestion on existing roads and highways. Among the traffic control devices that are utilized are variable speed limits, traffic metering lights, variable traffic signs and traffic signals. Traffic signals include changeable stop signs and stop lights. Speed limit signs may be made variable for example, by having a graphical display board which can receive a signal and change the appropriate speed limit based on traffic conditions. Metering lights are generally utilized on feeder roads onto highways. These lights control when a vehicle can enter a major highway.
While, in general, it is possible to design traffic control systems which account for normal patterns of traffic, whenever anything unusual happens existing traffic control patterns generally have problems. In the case of traffic accidents, bad weather conditions and special events, existing traffic control systems are not sufficiently adaptable to accommodate these conditions. As a result, traffic conditions worsen and severe delays may result.
Thus, there is a continuing demand for traffic control devices which facilitate the control of traffic under varying traffic conditions.
In accordance with one aspect of the present invention, a method for controlling traffic includes developing global positioning system information about a plurality of vehicles. Traffic patterns are analyzed based on the information. Traffic control signals are developed based on the traffic patterns and traffic control signals are transmitted to traffic control devices.